Pub Date : 1992-10-01DOI: 10.1109/IEMBS.1992.5761340
O. M. Rucci, M. Spuri, C. Perego
Menisci pathologies are more easily assessed if images represented on planes parallel to the menisci major section are examined. In the case of magnetic resonance imaging (MR), this procedure requires the physician to locate the plane where the two menisci approximately lie. Unfortunately, this operation is time-consuming and it is often accomplished by successive refinements. In this paper we propose a system for the automated location of such plane. The system works on sets of MR sagittal tomograms and includes three modules, two of which, those performing the image understanding tasks, are based on neural networks. Satisfactory results have been obtained with short computation time.
{"title":"A neural network system for menisci surface estimation in MR discrete 3D scenes","authors":"O. M. Rucci, M. Spuri, C. Perego","doi":"10.1109/IEMBS.1992.5761340","DOIUrl":"https://doi.org/10.1109/IEMBS.1992.5761340","url":null,"abstract":"Menisci pathologies are more easily assessed if images represented on planes parallel to the menisci major section are examined. In the case of magnetic resonance imaging (MR), this procedure requires the physician to locate the plane where the two menisci approximately lie. Unfortunately, this operation is time-consuming and it is often accomplished by successive refinements. In this paper we propose a system for the automated location of such plane. The system works on sets of MR sagittal tomograms and includes three modules, two of which, those performing the image understanding tasks, are based on neural networks. Satisfactory results have been obtained with short computation time.","PeriodicalId":6457,"journal":{"name":"1992 14th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"28 1","pages":"990-991"},"PeriodicalIF":0.0,"publicationDate":"1992-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82545707","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1992-10-01DOI: 10.1109/IEMBS.1992.5761116
J. Vila, S. Barro, J. Presedo, Ramón Ruiz, F. Palacios
Due to the proven efficiency of heart rate variability analysis as a non invasive method in the study of certain pathological and physiological states and given the multiplicity of the methods used by different authors, in this work we intend to compare two of the simplest and most efficient of them.
{"title":"Analysis of heart rate variability with evenly spaced time values","authors":"J. Vila, S. Barro, J. Presedo, Ramón Ruiz, F. Palacios","doi":"10.1109/IEMBS.1992.5761116","DOIUrl":"https://doi.org/10.1109/IEMBS.1992.5761116","url":null,"abstract":"Due to the proven efficiency of heart rate variability analysis as a non invasive method in the study of certain pathological and physiological states and given the multiplicity of the methods used by different authors, in this work we intend to compare two of the simplest and most efficient of them.","PeriodicalId":6457,"journal":{"name":"1992 14th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"30 1","pages":"575-576"},"PeriodicalIF":0.0,"publicationDate":"1992-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78679664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1992-10-01DOI: 10.1109/IEMBS.1992.5760887
M. Fernandez, R. Pallàs-Areny
Skin-Electrode interface noise is important in high resolution surface biopotential recordings. In order to determine its contribution, we have carried out several measurements. First, we measured the noise power spectrum density of several pairs of Ag/AgQ electrodes placed face to face and then placed on the body surface (leg and arm). We simultaneously measured the impedance of these pairs of electrodes and calculated the thermal noise associated to their real part. We found that noise at low frequencies is larger than noise at high frequencies, the power spectrum density increasing as 1/f. We have also found that calculated thermal noise is lower than measured electrode noise. Next, we measured noise and impedance for different electrode areas. For electrodes placed face to face we found that noise and resistance increase when electrode area decreases. For electrodes placed on the body surface, "noise" power spectrum density (probably EMG) increases when electrode area increases. We also calculated the Probability Density Function (PDF) of electrode noise. We found that it looks gaussian for electrodes placed face to face, but not for electrodes placed on the body surface.
{"title":"Electrode contact noise in surface biopotential measurements","authors":"M. Fernandez, R. Pallàs-Areny","doi":"10.1109/IEMBS.1992.5760887","DOIUrl":"https://doi.org/10.1109/IEMBS.1992.5760887","url":null,"abstract":"Skin-Electrode interface noise is important in high resolution surface biopotential recordings. In order to determine its contribution, we have carried out several measurements. First, we measured the noise power spectrum density of several pairs of Ag/AgQ electrodes placed face to face and then placed on the body surface (leg and arm). We simultaneously measured the impedance of these pairs of electrodes and calculated the thermal noise associated to their real part. We found that noise at low frequencies is larger than noise at high frequencies, the power spectrum density increasing as 1/f. We have also found that calculated thermal noise is lower than measured electrode noise. Next, we measured noise and impedance for different electrode areas. For electrodes placed face to face we found that noise and resistance increase when electrode area decreases. For electrodes placed on the body surface, \"noise\" power spectrum density (probably EMG) increases when electrode area increases. We also calculated the Probability Density Function (PDF) of electrode noise. We found that it looks gaussian for electrodes placed face to face, but not for electrodes placed on the body surface.","PeriodicalId":6457,"journal":{"name":"1992 14th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"45 1","pages":"123-124"},"PeriodicalIF":0.0,"publicationDate":"1992-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78934484","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1992-10-01DOI: 10.1109/IEMBS.1992.5760911
Shin-Won Kang, K. Sasaki, H. Minamitani
A simple method of determining the absorption coefficient of absorbing aqueous biochemicals is proposed as an application of the complex propagation constant of guided wave in a thin-film optical waveguide. It was designed to consecutively change the interaction length between the evanescent field and the sample, and evaluated by prism couplers. The response linearly depends on the interaction length and the total hemoglobin concentration (THb) of hemoglobin derivatives. The determined absorption coefficients fairly well coincide with the values obtained by the conventional transmission measurement.
{"title":"Determining the absorption coefficient of hemoglobin derivatives with integrated optic waveguide sensor","authors":"Shin-Won Kang, K. Sasaki, H. Minamitani","doi":"10.1109/IEMBS.1992.5760911","DOIUrl":"https://doi.org/10.1109/IEMBS.1992.5760911","url":null,"abstract":"A simple method of determining the absorption coefficient of absorbing aqueous biochemicals is proposed as an application of the complex propagation constant of guided wave in a thin-film optical waveguide. It was designed to consecutively change the interaction length between the evanescent field and the sample, and evaluated by prism couplers. The response linearly depends on the interaction length and the total hemoglobin concentration (THb) of hemoglobin derivatives. The determined absorption coefficients fairly well coincide with the values obtained by the conventional transmission measurement.","PeriodicalId":6457,"journal":{"name":"1992 14th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"39 1","pages":"171-172"},"PeriodicalIF":0.0,"publicationDate":"1992-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78961994","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1992-10-01DOI: 10.1109/IEMBS.1992.5761169
C. Renotte, M. Remy, P. Saucez, M. Mauroy
A mathematical model has been developed that describes the mechanical behavior of the human ventilatory system in healthy subjects under plethysmograph test conditions. We have shown that the introduction of the non-linear gas compression law into the mechanical model of the lung, while assuming air resistance to be a constant, leads to erroneous plethysmographic curves. When "volume-resistance" dependence is introduced, however, plethysmographic curves will then form the same shape as those usually recorded in healthy subjects. It is therefore evident that the semblance of linearity does not correspond with the more complex reality of the global behavior of the lung in which some non-linearities may offset each other.
{"title":"Compensation of two important non-linearities in the globally linear mechanical behavior of the human lung","authors":"C. Renotte, M. Remy, P. Saucez, M. Mauroy","doi":"10.1109/IEMBS.1992.5761169","DOIUrl":"https://doi.org/10.1109/IEMBS.1992.5761169","url":null,"abstract":"A mathematical model has been developed that describes the mechanical behavior of the human ventilatory system in healthy subjects under plethysmograph test conditions. We have shown that the introduction of the non-linear gas compression law into the mechanical model of the lung, while assuming air resistance to be a constant, leads to erroneous plethysmographic curves. When \"volume-resistance\" dependence is introduced, however, plethysmographic curves will then form the same shape as those usually recorded in healthy subjects. It is therefore evident that the semblance of linearity does not correspond with the more complex reality of the global behavior of the lung in which some non-linearities may offset each other.","PeriodicalId":6457,"journal":{"name":"1992 14th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"39 1","pages":"681-683"},"PeriodicalIF":0.0,"publicationDate":"1992-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78973787","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1992-10-01DOI: 10.1109/IEMBS.1992.5762197
B. Branger, M. Dauzat, B. Zabadani, F. Vécina, J. Fourcade
Serious complications may occur after "blind" profound venous puncture in intensive care units. To securize these punctures, we designed a new fingertip pulsed doppler 4 MHz probe with a lateral to center indentation to guide the needle into the ultrasonic flux. A specific ultrasound analyzer indicating depth and diameter of the vessel was made for this use. This material was first tested in an experimental animal study. Results of animal venous punctures were successfull 20/21. This material was then tested on patients with previous failure of "blind" punctures: results of fingertip pulsed doppler guided (FPDG) punctures were successfull in all cases but one (catheterisation not completed). We started a prospective multi-unit randomized study with various operators (junior residents, senior staff members), compared the success rate, the complication rate and type, the procedure duration of blind standard verSUS FPDG punctures. We conclude in the safety and easy use of the FPDG central venous punctures.
{"title":"Safe continuous ultrasonic guidance of venous punctures with a new finger-tip pulsed doppler probe","authors":"B. Branger, M. Dauzat, B. Zabadani, F. Vécina, J. Fourcade","doi":"10.1109/IEMBS.1992.5762197","DOIUrl":"https://doi.org/10.1109/IEMBS.1992.5762197","url":null,"abstract":"Serious complications may occur after \"blind\" profound venous puncture in intensive care units. To securize these punctures, we designed a new fingertip pulsed doppler 4 MHz probe with a lateral to center indentation to guide the needle into the ultrasonic flux. A specific ultrasound analyzer indicating depth and diameter of the vessel was made for this use. This material was first tested in an experimental animal study. Results of animal venous punctures were successfull 20/21. This material was then tested on patients with previous failure of \"blind\" punctures: results of fingertip pulsed doppler guided (FPDG) punctures were successfull in all cases but one (catheterisation not completed). We started a prospective multi-unit randomized study with various operators (junior residents, senior staff members), compared the success rate, the complication rate and type, the procedure duration of blind standard verSUS FPDG punctures. We conclude in the safety and easy use of the FPDG central venous punctures.","PeriodicalId":6457,"journal":{"name":"1992 14th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"213 1","pages":"2122-2123"},"PeriodicalIF":0.0,"publicationDate":"1992-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76523330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1992-10-01DOI: 10.1109/IEMBS.1992.5762122
O. Henriksen, P. Christiansen, H. Larsson, M. Stubgaard
A method is presented for in vivo quantification of some brain metabolites detected by water suppressed volume selected proton MR-spectroscopy using the unsaturated water signal as internal standard. In vitro as well as studies on 17 healthy volunteers were carried out. The results indicated that the concentration of N-acetyl aspartate, creatine + phosphocreatine, choline containing compounds and inositols could be determined reasonably with this first order approximation.
{"title":"In vivo quantitative 1H-MRS of metabolites in the brain using water as internal standard","authors":"O. Henriksen, P. Christiansen, H. Larsson, M. Stubgaard","doi":"10.1109/IEMBS.1992.5762122","DOIUrl":"https://doi.org/10.1109/IEMBS.1992.5762122","url":null,"abstract":"A method is presented for in vivo quantification of some brain metabolites detected by water suppressed volume selected proton MR-spectroscopy using the unsaturated water signal as internal standard. In vitro as well as studies on 17 healthy volunteers were carried out. The results indicated that the concentration of N-acetyl aspartate, creatine + phosphocreatine, choline containing compounds and inositols could be determined reasonably with this first order approximation.","PeriodicalId":6457,"journal":{"name":"1992 14th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"1 1","pages":"1964-1965"},"PeriodicalIF":0.0,"publicationDate":"1992-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76530809","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1992-10-01DOI: 10.1109/IEMBS.1992.5760901
I. Dendo
Streaming potential is generated between the both sides of a glass-capillary or a glass-filter filled with an aqueous solution as a hydrostatic pressure is applied. In this paper, an application of the phenomenon to a micro-dimensional pressure sensor (tip diameter: about 1 μm) for biophysiological measurements, is presented. Blood pressure are measured in toad's mesenteric arteries.
{"title":"A micro-dimensional tip streaming potential pressure sensor","authors":"I. Dendo","doi":"10.1109/IEMBS.1992.5760901","DOIUrl":"https://doi.org/10.1109/IEMBS.1992.5760901","url":null,"abstract":"Streaming potential is generated between the both sides of a glass-capillary or a glass-filter filled with an aqueous solution as a hydrostatic pressure is applied. In this paper, an application of the phenomenon to a micro-dimensional pressure sensor (tip diameter: about 1 μm) for biophysiological measurements, is presented. Blood pressure are measured in toad's mesenteric arteries.","PeriodicalId":6457,"journal":{"name":"1992 14th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"110 1","pages":"151-152"},"PeriodicalIF":0.0,"publicationDate":"1992-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75974090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1992-10-01DOI: 10.1109/IEMBS.1992.5761494
D. Raković
It is shown that neural networks with embedded brainwaves can cross the gap between the fast parallel unconscious mode of neuroscience and the slow serial conscious mode of psychology. The electromagnetic (EM) component of extremely low frequency (ELF) brainwaves appears to enable perfect fitting with narrowed limits of conscious capacity in normal awake states and very extended limits in altered states of consciousness — due to the biophysical relativistic mechanism of dilated subjective time base. It also enables the mixing of the normally conscious and unconscious contents in altered states, due to the relativistic Doppler mapping of EM component of the "objective" ELF brainwave power spectrum on the zero-degenerate frequency "subjective" one. All that provides an excellent biophysical basis for dream-like altered states of consciousness, and reveals the nature and significance of dreams and intentionally prolonged dream-like altered states.
{"title":"Neural networks versus brainwaves: A model for dream-like states of consciousness","authors":"D. Raković","doi":"10.1109/IEMBS.1992.5761494","DOIUrl":"https://doi.org/10.1109/IEMBS.1992.5761494","url":null,"abstract":"It is shown that neural networks with embedded brainwaves can cross the gap between the fast parallel unconscious mode of neuroscience and the slow serial conscious mode of psychology. The electromagnetic (EM) component of extremely low frequency (ELF) brainwaves appears to enable perfect fitting with narrowed limits of conscious capacity in normal awake states and very extended limits in altered states of consciousness — due to the biophysical relativistic mechanism of dilated subjective time base. It also enables the mixing of the normally conscious and unconscious contents in altered states, due to the relativistic Doppler mapping of EM component of the \"objective\" ELF brainwave power spectrum on the zero-degenerate frequency \"subjective\" one. All that provides an excellent biophysical basis for dream-like altered states of consciousness, and reveals the nature and significance of dreams and intentionally prolonged dream-like altered states.","PeriodicalId":6457,"journal":{"name":"1992 14th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"23 1","pages":"2651-2652"},"PeriodicalIF":0.0,"publicationDate":"1992-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87542100","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1992-10-01DOI: 10.1109/IEMBS.1992.5761652
Olivier Meste, Hervé Rix, M. Perrone
Matched Filtering is currently used for Time Delay Estimation between a repetitive signal and a template obtained by synchronous averaging. We propose an analysis of the effect of the estimation of the template by signal averaging on the final averaged signal. We give a sufficient condition which has to be verified by the jitter occuring in the averaging process. This condition often verified practically is sufficient to avoid biased results. The disturbing effect will be illustrated by simulation using a noiseless gaussian signal.
{"title":"Alignment process using correlation influence of template estimation","authors":"Olivier Meste, Hervé Rix, M. Perrone","doi":"10.1109/IEMBS.1992.5761652","DOIUrl":"https://doi.org/10.1109/IEMBS.1992.5761652","url":null,"abstract":"Matched Filtering is currently used for Time Delay Estimation between a repetitive signal and a template obtained by synchronous averaging. We propose an analysis of the effect of the estimation of the template by signal averaging on the final averaged signal. We give a sufficient condition which has to be verified by the jitter occuring in the averaging process. This condition often verified practically is sufficient to avoid biased results. The disturbing effect will be illustrated by simulation using a noiseless gaussian signal.","PeriodicalId":6457,"journal":{"name":"1992 14th Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":"118 1","pages":"2730-2731"},"PeriodicalIF":0.0,"publicationDate":"1992-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87600013","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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